Understanding Diabetes
37.3 million Americans struggle with diabetes: 28.7 million diagnosed, and 8.5 million undiagnosed. Left untreated diabetes can lead to many complications, such as organ damage and nerve damage.
What is diabetes?
Diabetes is a medical condition characterized by an excessive amount of glucose (increased amount of blood sugar) production in your blood due to reduced/impaired insulin production, and/or your body doesn’t effectively use the amount of insulin it does make.
Symptoms
- Increased thirst
- Increased hunger/appetite
- Increased urination, typically at night (known as “polyuria”)
- Weight loss
- Blurred vision
- Extreme fatigue
- Numb and/or tingling sensation in your hands and/or feet
- Dry skin
- Sores that heal slowly
- Experience more infections than usual
- Some women may experience symptoms such as urinary tract infection (UTI) and/or yeast infection
- Some men may experience symptoms such as reduced sex drive, erectile dysfunction, and/or decrease muscle strength.
- In type 1 diabetes, typically in children, diabetic ketoacidosis (DKA) is generally the initial presentation and is caused by a total deficiency in insulin.
Diabetes testing
Through blood testing, your healthcare provider can determine whether you have diabetes, prediabetes, or gestational diabetes. The criteria for diagnosing diabetes are based on the type of test used (no single test is preffered over the other). Each test usually needs to be repeated on a second day.
Diagnosis should be confirmed for fasting plasma glucose (FPG), oral glucose tolerant test (OGTT) and A1C. Normal test results should be repeated at least every 3 years.
Fasting plasma glucose (FPG)—checks fasting blood sugar levels. “Fasting” means no caloric intake for at least 8 hours (except water). Typically, this test is done first thing in the morning.
| Fasting plasma glucose (FPG) | |
| Normal | less than 100 mg/dl (5.3 mmol/L) |
| Prediabetes | 100 mg/dl – 125 mg/dl (5.3–6.9 mmol/L) |
| Diabetes | 126 mg/dl (7 mmol/L) or higher |
Oral glucose tolerant test (OGTT)—a two-hour test checks blood glucose levels before and after you drink a liquid containing a certain amount of glucose. The test tells how your body processes sugar.
| Oral Glucose Tolerance Test (OGTT) | |
| Normal | less than 140 mg/dl (7.8 mmol/L) |
| Prediabetes | 140 mg/dl – 199 mg/dl (7.8–11 mmol/L) |
| Diabetes | 200 mg/dl (11 mmol/L) or higher |
Hemoglobin A1C—measures your average glucose control over the past 3 months.
| A1C | |
| Normal | less than 5.7% |
| Prediabetes | 5.7% – 6.4% |
| Diabetes | 6.5% or higher |
Risk factors for diabetes
Type 1 diabetes
- Age: most common in children, adolescents, or young adults, however, can also occur at any age
- Family history
Type 2 diabetes
- Prediabetes
- Overweight and/or obese (BMI ≥ 25 kg/m2)
- Age: 45 years old and above
- Family history/first-degree relative with type 2 diabetes
- Sedentary lifestyle/physically inactive (active less than 3 times a week)
- Smoking
- History of cardiovascular disease (CVD)
- Race/ethnicity: African American, Latino, Native American, Asian American, and/or Pacific Islander)
- History of gestational diabetes mellitus (diabetes during pregnancy)
Types of diabetes
Type 1 diabetes
Type 1 diabetes comprises approximately 5%–10% of all cases of diabetes. It is caused by autoimmune destruction of the beta-cells in your pancreas. Insulin is created by beta cells; if these cells are damaged, insulin production is stopped.
Without insulin, blood sugar cannot enter muscle cells and fat is used as an alternate energy source. Fat breakdown produces ketones, and the ketones can cause diabetic ketoacidosis (DKA—your body produces too many blood acids called ketones), which is life-threatening. People with type 1 diabetes must be treated with insulin and should be screened for other autoimmune disorders, such as thyroid disorders and celiac disease.
Type 1 diabetes normally presents in younger, thinner individuals, however, it can also occur in older individuals as well.
The biggest risk factor for type 1 diabetes is family history, for example, having a parent, sister, and/or brother with type 1 diabetes.
The C-peptide test is used to distinguish the difference between type 1 and type 2 diabetes, especially early on in the disease when it’s difficult to differentiate between the two. This test is used to measure whether or not you still produce insulin.
Type 2 diabetes
Type 2 diabetes comprises approximately 95% of cases and is due to both insulin resistance (reduced insulin sensitivity) as well as insulin deficiency.
Your pancreatic beta cells produce less insulin over time as they become damaged. High glucose levels gradually develop and this is why the onset of type 2 diabetes is often gone unnoticed.
Type 2 diabetes is strongly associated with obesity, physical inactivity, family history, and the presence of other denoting medical conditions.
Type 2 diabetes is often diagnosed in older people and can be managed with lifestyle modifications alone, such as healthy eating/diet and increased exercise, or in combination with medications.
Learn about medication options for Type 2 diabetes.
Prediabetes
Prediabetes is when you have an increased risk of developing diabetes, for example, your blood sugar levels are higher than normal, but it’s not high enough to be diagnosed as type 2 diabetes.
By following the right exercise and diet recommendations, you can reduce the risk of progressing from prediabetes to diabetes.
Gestational diabetes (diabetes during pregnancy)
Gestational diabetes consists of women who develop diabetes during pregnancy, otherwise known as gestational diabetes mellitus (GDM), or women who had diabetes prior to becoming pregnant, referred to as pre-gestational diabetes.
All forms of gestational diabetes include blood glucose targets that are more strict than the targets for the non-pregnant population with diabetes to keep the mother and the baby healthy.
If a pregnant woman has uncontrolled diabetes, the baby can be large (macrosomia), will be at a higher risk of developing glucose deficiency at birth, and will have an increased risk for childhood obesity and type 2 diabetes.
Women who develop GDM have an increased risk of developing type 2 diabetes later in their life
To manage your diabetes while pregnant, proper lifestyle modifications, such as diet and exercise, are recommended. Repeatedly self-monitoring your blood glucose (SMBG) is used to assess if lifestyle modifications are adequate, if not, then insulin treatment is recommended.
Goals for diabetes in pregnancy
- Fasting: ≤ 95 mg/dL (5.3 mmol/L)
- 1 hour after meals: ≤ 140 mg/dL (7.8 mmol/L)
- 2 hours after meals: ≤ 120 mg/dL (6.7 mmol/L)